Alan Deyermond published in 1977 in the pages of La corónica "The Lost Literature of Medieval Spain: Excerpts from a Tentative Catalogue," a groundbreaking article in which he offered a glimpse of a work in progress. The present article provides an analysis of that piece, puts it in the wide context of Deyermond's research production on that particular topic, examines the trajectory of that research line in Deyermond's wider research, and offers some information and conjectures about the ending of that particular research line.